In order to better record ancillary information about captured images, some film cassettes have an internal electronic memory, which is written to by a microprocessor in a camera. Good electrical contact must be maintained in the camera between a series of fixed contacts on the memory and a series of leads in the camera. To reduce overall camera and film cassette size, the parts involved are quite small. Misalignment easily occurs unless all parts are precisely made.
A very large number of cameras use Type 135 ("35 mm ") film. Type 135 film cassettes are defined by the standard: ANSI PH1.14M-1983 promulgated by the American National Standards Institute, Inc. of New York, N.Y. This standard provides for a substantially cylindrical cassette shell having an exposed spool portion protruding from each end of the shell and a shell slot at each end around the exposed spool portion. The slot is open-topped and roughly discoidal in shape having an empty discoidal center to accommodate the spool portion.
Electronic memory could be mounted to a Type 135 film cassette, however, this is problematic. Film cassettes are not ordinarily returned when Type 135 film is processed. Information recorded in memory, but not used in processing, would be lost if a cassette having electronic memory was discarded. Returning the memory in an empty cassette shell would be possible, but cumbersome. Replacement memory could be provided in some form, but this would be costly or cumbersome or both.
It would thus be desirable to provide means for reading a removable film cassette electronic memory while the memory is separated from the cassette.